Method and dobby for weaving mixed weave fabrics

ABSTRACT

A method of operating a loom having heald frames operable to three positions comprising a lower shed position and an upper shed position for effecting a normal weave and a half shed position intermediate the other two positions for effecting a leno weave. The loom has a first and a second operating mechanism for weaving mixed fabrics.

United States Patent Rudoll Schwarz Bergen-Zurich, Switzerland [21] AppLNo. 813,888

[72] Inventor [22] Filed Apr. 7, 1969 [45] Patented Oct. 12, 1971 [73] Assignee Staubli Ltd.

Zurich, Switzerland [32] Priority Apr. 8, 1968 [33] Switzerland [54] METHOD AND DOBBY FOR WEAVING MIXED WEAVE FABRICS 1 1 Claims, 11 Drawing Figs.

[52] US. Cl 139/50 [51] Int. Cl D03c 7/00 [50] Field of Search 139/50,48, 49, 66, 79, 80, 56

[56] Reierenccs Cited UNITED STATES PATENTS 386,477 7/1888 Littlefield 139/50 890,612 6/1908 139/50 1,543,045 6/1925 Bachman et al. 139/50 1,719,911 7/1929 Tetreault 139/50 Primary ExaminerJames Kee Chi Attorneys-Robert E. Burns and Emmanuel J. Lobato ABSTRACT: A method of operating a loom having heald frames operable to three positions comprising'a lower shed position and an upper shed position for effecting a normal weave and a half shed position intermediate the other two positions for effecting a leno weave. The loom has a first and a second operating mechanism for weaving mixed fabrics.

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METHOD AND DOBBY FOR WEAVING MIXED WEAVE FABRICS This invention relates to a method and a dobby with a rocking device for controlling the movement of standard frames for the manufacture of mixed weave fabrics with leno weave and normal weave, with dobby or jacquard machines, where both return spring and double lift dobbies are used, in the latter, however, without positive control of the standard frames.

For the manufacture of leno weaves with dobbies there occurs a raising of the standard frames on closing the shed into the half shed, or somewhat higher, in order to allow the leno halfhealds free passage on raising the leno shaft.

In the known dobbies, if it is a question of leno weaves, the control of the standard frames takes place by means of a cam. Now, if after a leno weave there is a transfer to normal weave, then after the crossing of the shed the standard frame which has already been raised above half way and which is falling again is further controlled by the normal operating parts of the shafts and is raised into the upper shed. As is shown later with reference to a diagram, this transfer of the shaft movement from the rocking device for the standard frames to the shaft movement by the control mechanism of the dobby occurs abruptly, which on the one hand does not allow an increase of the operating speed, and on the other hand leads to uneven running and excessive wear and tear to the healds or heddles.

However, on transferring from leno weave'to normal weave, it has also been proposed that the standard frame is allowed to move along its entire path only by the normal shaft control mechanism. However, this requires an additional, complicated arrangement for stopping the action of the rocking device.

The object of the invention is an impact-free transfer of the standard frames from their movement produced by the rocking device as far as the half shed, or slightly above it, into the shaft movement produced by the normal shaft control mechanism of the dobby, for reaching the upper shed as well as the impact-free taking over of the movement of the standard frames by the rocking device when the vertical shafts are descending from the upper shed into the lower shed. This object is achieved with the method according to the invention, which is distinguished in that the transfer of the movement of the standard frame, which is produced by the rocking device, to the movement of this shaft for reaching the upper shed occurs without impact.

For carrying out this method there serves a dobby, in which on the known swing lever for the shaft operation for a normal weave a drive is attached. One element of this drive acts on a moving part between the rocking device and the shaft. During the reciprocating motion of the swing lever the drive which is linked to it causes a displacement of the moving parts of the shaft for the purpose of an impact-free further, similarly directed raising or lowering of the standard frame.

As a drive between the known shaft operating mechanism of the dobby for normal weave and the likewise known rocking device there can serve any construction, which converts the movement of the swing lever of the dobby into a support movement of the rocking device. The drive can consist of toggle levers, sliding wedges or swinging cam disks.

Two embodiments of the object of the invention are described with reference to the drawings.

FIG. 1 is a diagram of the shaft movements on transferring from leno weave to normal weave in a dobby with a rocking device;

FIG. 2 is the same diagram of a dobby according to the invention;

FIGS. 3-6 are a diagrammatic illustration of a dobby with a rocking device for the standard frame as well as a lever device according to the invention given as an example with a wedge in four different positions according to the diagram;

FIGS. 7-10 are a modification according to FIGS. 3-6, the wedge being replaced by a cam disk; and

F l0. 11 is the diagrammatic construction of a further modification with a toggle lever.

diagram of FIG. 1 are indicated with the index The curve N, g respectively N, and N respectively N show the sequence of movements of a normal shaft controlled by a dobby, the curve 8 respectively S shows that a standard frame controlled by an associated rocking device. At A the crossing of the shed occurs. H is the position of the upper shed, T of the lower shed. The diagrams are read from left to right.

If leno weave is worked continuously, then the standard frame swings through the curve indicated by S or S respectively, and at the shed crossing A of the normal shafts N, it is located above the shed crossing point, i.e. the shaft is located in the so-called half shed.

Now if, in a known dobby with a rocking device, on the next following pick, there is a transfer from leno weave to normal weave-movement path of the standard frame S shown in thick black linethen previously this occurred according to the diagram of FIG. 1 so that after the crossing of the shed the standard frame S is picked up by the shaft control mechanism of the dobby, which according to the diagram occurred at the point M,. It can be seen that the standard frame is thus suddenly picked up out of its downward movement into an upward movement. This can only take place by means of an abrupt transfer. This impact leads to disturbance in the shafts and also to extensive wear and tear on the entrainment rod as well assignificant wear of the healds. The same impact also occurs at M,, when there is a transfer from nonnal weave back to leno weave.

FIG. 2 shows that in the dobby according to the invention the point M, has been moved to the ascending branch of the trajectory of the vertical shaft s', which gives a continuous shaft movement. The same applies for the point M,'. This shifting of the transfer of movement from one control mechanism to the other mechanism has no effect on the weave, however it allows more even running of the machine despite an increased operating speed.

in addition a comparison of the two diagrams shows that the mechanism, which carries along the standard frame S on the path 5', no longer controls the same path as for a normal shaft N Since the mechanism according to the invention operates spontaneously from the lower shed to approximately the half shed at the point M, without stress from the shaftthe shaft is always taken along this path by the rocking device-it has no high mass accelerative force to exert. Thus it can follow the steeper path in the diagram and during its equidirectional movement at the point M, takes the shaft along, in order to raise it into the upper shed. From M, as far as the upper shed and back to M, the rocking device-has no effect on the standard frame.

Without going into the position of the entire apparatus, for the present, the individual parts will be described in greater detail with reference to FIG. 3.

The shaft operating mechanism for normal weave-known under the name of the Hattersley Systemconsists of the drawknives 2, which swing to and fro about the driving shaft 1, which depending on the control according to the pattern take along the draw hooks 3. The latter are attached to the ends of the baulk 4, on which in the center thereof engages the swing pivotal shaft 6 mounted on the lever 5. Now in a dobby without a rocking device from the end 7 of the swing lever the traction means lead directly or by means of another heald lever to the heald frame 8. The rocking device for standard frames illustrated in FIG. 3 is composed of the cam 9, which rotates with the cam shaft 10 and on which the roller 11 of the rod 12 slides. The movement produced by the cam 9 is imparted to the heald frame 8 by means of the two-armed tilting lever 13 and the traction rod or traction cable 14, and a return spring 15 is provided.

To the lever device l6-18 according to the invention there belong only the connecting parts between the shaft operating mechanism for normal weave 1-7 and the rocking device 9- 13, Le. the rod 16, which is attached to the swing lever 6, as well as the wedge 17 attached to it, which slides on the surface 18. In addition the follower 19 of the rod 12 is constructed as a roller.

FIGS. 3-6 show momentary situations, from which there can be seen the cooperation of the rocking device, of the normal shaft operating mechanism and of the lever device for taking over the control of the movement of the heald frame from the device to the mechanism. All the parts shown are associated with the standard frame 8 corresponding to the curves S, S and S. The curves N, and N, belong to two different heald frames, which have their own control and operating parts. In the diagrams of FIGS. 1 and 2 there are shown the positions which correspond to the individual momentary situations of FIGS. 3-6.

FIG. 3 shows the position of the moving parts during the crossing of the shed, i.e. the drawknives 2 are located in their central position of the swinging movement. However, since a pure leno weave is being undertaken, there are no drawhooks 3 attached to the drawknives 2. The heald frame 8 has been raised into the half shed position by the rocking device and has covered approximately 60-70 percent of the total movement.

FIG. 4 shows the position of the moving parts at the moment of the insertion of the pick, preparations already having been made for transferring from leno weave to normal weave for the next pick. By means of the cam 9 and the tension spring 15 the standard frame 8 was brought into the lower shed position. The drawhook is attached to the upper drawknife 2.

FIG. shows the position of the moving parts at the moment of the taking over of the control of the movement of the standard frame from the rocking device 9-13 by the operating mechanism 1-7 of the dobby by means of the lever device 16-19. In the diagram this occurs at the point M The cam 9, which rotates in the direction indicated by the arrow, has not quite raised the heald frame 8. The upper drawknives 2 move in the direction of the arrow and by means of the drawhook 3 and the baulk 4 carries along the swing lever 6. The latter, by means of the rod 16 pushes the wedge 17 under the follower 19. There is now a problem of adjustment at which moment the sloping surface of the wedge 17 raises the follower l9 and thus the rod 12.

FIG. 6 shows, the position of the moving parts at the moment of the insertion of the pick for a normal weave, i.e. the standard frame has been raised into the upper shed by the operating mechanism of the dobby 1-7 and by means of the rod 16, the wedge 17, the tilting lever 13 and the traction rod 14. The cam 9 of the rocking device no longer affects the position and movement of the shaft 8.

The return of the heald frame according to the continuation of the curve S takes place in the reversed order, the wedge 17 being moved back and at the point M, the roller 11 coming to lie on the cam 9.

In FIGS. 7 to a variation is shown, once more in four different positions, with regard to FIG. 2 the positions in FIGS. 7 to 10 corresponding to the positions in FIGS. 3'to 6. Exactly corresponding parts of the two variations have the same reference numerals.

The known shaft operating mechanism for normal weave consists of the drawknives 2, which swing to and fro about the driving shaft 1, and the drawhooks 3 controlled according to the pattern, which are attached to the baulk 4. At the end of the swing lever 6, which is supported on the bearing 5, the rod 26 is attached. On the shaft 28 there is pivoted the cam disk 27, which comes into contact with the roller 29.

The known rocking device for standard frames consists of the cam 9, which rotates continuously with the cam 10 and thus imparts its tilting motion to the arm 22 of the three-armed tilting lever 23 together with the return spring 15. This tilting motion is transmitted through the traction cable 14, as in FIG. 3, to the standard frame 8.

FIG. 7 shows the position at the crossing of the shed, where the dobby controls a purely leno weave. The drawknives 2 are not carrying along the drawhooks. Only the rocking device 9, I0, 23 with the traction cable 14 and the spring are acting on the heald frame 8.

Now if the heald frame is to be raised into the upper shed, according to FIG. 8 after the upper drawhook 3 has been carried along by the drawl'mife 2 the swing lever 6 by means of the rod 26 produces a swinging movement of the cam disk 27.

FIG. 8 illustrates the moment of the initiation of the movement. The upper drawhook 3 has been controlled according to the pattern for attaching on the drawknife 2. As a continuation of this FIG. 9 shows how the follower 29 which is lying on the cam disk 27 is raised, by means of which there occurs an increase of the swinging movement of the tilting lever 23. The arm 22 then no longer lies on the cam 9 (FIG. 10).

As long as leno weave is worked, the rocking device 9, 10,

22, 23 controls the heald frame. The raising of the heald frame into the upper shed takes place by the shaft operating mechanism of the dobby through the swing lever 6, the rod 26, the cam disk 27, the follower 29 and the tilting lever 23.

FIG. 11 shows a further embodiment of the lever device 36, which is attached to the shaft operating mechanism l-7 for normal weave and which acts on a moving part 33, 14 between the rocking device 9, 10, 32, 33 and the heald frame 8. All the parts identical to the first two embodiments have the same reference numeral. At 7 there is attached to the swing lever 6 the rod 36, which has a fork 37 at its upper end. In this fork there is arranged the joint 39 of the toggle lever 40, the two ends of the toggle lever being attached to the shaft 38 and to the. double lever 33 respectively.

If only the rocking device is working, then the joint 39 slides up and down in the fork 37 without effecting the movement of the standard frame. Now if the standard frame is to be raised into the upper shed, then the swing lever 6 produces a lifting of the fork, which transmits its movement to the double lever 33 by means of the joint 39 and the toggle lever 40. There thus occurs the taking over of the movement of the standard frame from the rocking device by the shaft operating mechanism.

Instead of acting on the toggle lever, the rod 36 can act directly, or with the interposition of a further lever, on the traction cable 14, in that the lever device widens the traction cable out from being straight e.g. between the double lever 33 and the heald frame 8.

In all the embodiments which are described and illustrated, in the lever device according to the invention, i.e. in the parts connecting the rocking device to the shaft operating mechanism of the dobby, there are possibilities for adjustment, in order to vary the points M, and M, within certain limits and to adapt the two movement mechanisms to each other. These possibilities for adjustment are:

l. Altering the length of the rods 16, 26, 36

2. Adjusting the mounting of the cam, i.e. adjusting the height of the sliding surface 18 of the wedge 17, or adjusting the rocking shaft 28 of the cam disk 27, or adjusting the bearing 38 of the toggle lever 40, according to the arrow A.

3. Altering the cam shape by exchanging the wedge 17 or by altering the inclination of the sliding surface 18 or changing the cam disk 27 or altering the fork or the toggle lever.

Thus it is also possible to adapt the given lifting curve of the known shaft operating mechanism of the dobby to the lifting curve of the known rocking device, in particular close to the point M respectively M,.

In addition to the impact-free transfer from a known movement mechanism (rocking device) to the other known movement mechanism (shaft operating mechanism of the dobby) the lever device according to the invention also has the advantage that only one traction rod leads to the heald frame and that the two mechanisms are as near as possible to the heald frame for working, i.e. to the tilting lever 13 or 23 or 33 or direct on the drawhook or driving shaft. The arrangement is very simple in its entire construction, and it combines only known and tried mechanisms. It allows a considerable increase in the operating speed to be achieved.

While preferred embodiments of the invention have been shown and described it will be understood that many modifications and changes can be made within the true spirit and scope of the invention.

lclaim:

l. A method of operating a loom having heald frames operable to three operating positions comprising a lower shed position, an upper shed position for effecting a normal weave and a half shed position intermediate the lower shed position and upper shed position for effecting a leno weave and heald levers operable to three positions corresponding to respective ones of the three operating positions of a respective one of said heald frames, the loom having a first operating mechanism and a second mechanism for alternately operating a given heald frame for weaving mixed fabrics, said method comprising actuating the heald lever with the first operating mechanism from a first position corresponding to said lower shed position of said heald frame to a second position corresponding to the half shed position of said heald frame, disengaging the heald lever from the first operating mechanism with said second operating mechanism without interruption of movement of said heald lever and continuing uninterrupted, smooth movement of said heald lever to a third position corresponding to said upper shed position of said heald frame, returning the heald lever from its third position to its second position under control of the second operating mechanism, engaging the heald lever with the first operating mechanism with said second operating mechanism, and continuing actuation of said heald lever smoothly and without interruption from its second position to its first position under control of said first mechanism, and repeating actuation of said heald lever from its first position to its third position and back to its first position.

2. A method according to claim 1, in which said heald lever is actuated substantially at the same speed by said first operating mechanism and said second operating mechanism.

3. ln a loom for weaving mixed weave fabrics having a leno weave and a normal weave, in combination, a heald frame operable from a lower shed position, to an upper shed position and an intermediate half shed position, a heald lever actuating the heald frame from said lower shed position to said half shed position and to said upper shed position and returning it to said lower shed position, a rocking device cooperative with said heald shaft actuating said heald lever to move the heald frame from the lower shed position to the half shed position and back to the lower shed position, a second drive mechanism having transfer means effective to render ineffective actuation of said heald lever by said rocking device and smoothly transfer actuation of said heald lever by said second drive mechanism without interruption of movement of said heald lever to effect movement of the heald frame from said half shed position to said upper shed position under control of said second drive mechanism and for returning control of the movement of the heald lever and heald frame to said rocking device when the heald frame is moved between said intermediate shed position and lower shed position.

4. In a loom according to claim 3, in which said second drive mechanism transfer means comprises a driven element driven selectively cooperating with said rocking device uncoupling said heald lever from the rocking device and recoupling it therewith smoothly without interruption of movement of said heald lever.

5. In a loom according to claim 4, in which said heald lever is disposed for movement along a predetermined path of travel.

6. In a loom according to claim 5, in which said transfer means is disposed spaced from said path of travel of the heald lever and includes means for selectively moving said driven element into said path of travel and out of said path of travel, said driven element having means thereon to move the heald lever along its path of travel between positions corresponding to the half shed and upper shed positions of the heald frame.

7. In a loom according to claim 6, in which said element comprises a reciprocably driven wedge insertable selectively into the rocking device to uncouple and couple the heald lever to said rocking device.

. In a loom according to cla m 6, in which said driven element comprises a cam, and said means thereon comprises a camming surface.

9. In a loom according to claim 8, in which said cam comprises a wedge-shaped cam and said camming surface thereon comprises an inclined camming surface controlling actuation and travel of said heald lever.

10. In a loom according to claim 8, in which said cam and in which said camming surface thereon comprises an arcuate camming surface controlling actuation and travel of said heald shaft lever.

11. In a loom according to claim 8, in which said rocking device comprises a cam follower connected to said heald lever and coupling the heald lever to said rocking device, and said transfer means comprises means engaging said cam in said transfer means to said cam follower transferring control of the heald lever between the rocking device and the second drive mechanism. 

1. A method of operating a loom having heald frames operable to three operating positions comprising a lower shed position, an upper shed position for effecting a normal weave and a half shed position intermediate the lower shed position and upper shed position for effecting a leno weave and heald levers operable to three positions corresponding to respective ones of the three operating positions of a respective one of said heald frames, the loom having a first operating mechanism and a second mechanism for alternately operating a given heald frame for weaving mixed fabrics, said method comprising actuating the heald lever with the first operating mechanism from a first position corresponding to said lower shed position of said heald frame to a second position corresponding to the half shed position of said heald frame, disengaging the heald lever from the first operating mechanism with said second operating mechanism without interruption of movement of said heald lever and continuing uninterrupted, smooth movement of said heald lever to a third position corresponding to said upper shed position of said heald frame, returning the heald lever from its third position to its second position under control of the second operating mechanism, engaging the heald lever with the first operating mechanism with said second operating mechanism, and continuing actuation of said heald lever smoothly and without interruption from its second position to its first position under control of said first mechanism, and repeating actuation of said heald lever from its first position to its third position and back to its first position.
 2. A method according to claim 1, in which said heald lever is actuated substantially at the same speed by said first operating mechanism and said second operating mechanism.
 3. In a loom for weaving mixed weave fabrics having a leno weave and a normal weave, in combination, a heald frame operable from a lower shed position, to an upper shed position and an iNtermediate half shed position, a heald lever actuating the heald frame from said lower shed position to said half shed position and to said upper shed position and returning it to said lower shed position, a rocking device cooperative with said heald shaft actuating said heald lever to move the heald frame from the lower shed position to the half shed position and back to the lower shed position, a second drive mechanism having transfer means effective to render ineffective actuation of said heald lever by said rocking device and smoothly transfer actuation of said heald lever by said second drive mechanism without interruption of movement of said heald lever to effect movement of the heald frame from said half shed position to said upper shed position under control of said second drive mechanism and for returning control of the movement of the heald lever and heald frame to said rocking device when the heald frame is moved between said intermediate shed position and lower shed position.
 4. In a loom according to claim 3, in which said second drive mechanism transfer means comprises a driven element driven selectively cooperating with said rocking device uncoupling said heald lever from the rocking device and recoupling it therewith smoothly without interruption of movement of said heald lever.
 5. In a loom according to claim 4, in which said heald lever is disposed for movement along a predetermined path of travel.
 6. In a loom according to claim 5, in which said transfer means is disposed spaced from said path of travel of the heald lever and includes means for selectively moving said driven element into said path of travel and out of said path of travel, said driven element having means thereon to move the heald lever along its path of travel between positions corresponding to the half shed and upper shed positions of the heald frame.
 7. In a loom according to claim 6, in which said element comprises a reciprocably driven wedge insertable selectively into the rocking device to uncouple and couple the heald lever to said rocking device.
 8. In a loom according to claim 6, in which said driven element comprises a cam, and said means thereon comprises a camming surface.
 9. In a loom according to claim 8, in which said cam comprises a wedge-shaped cam and said camming surface thereon comprises an inclined camming surface controlling actuation and travel of said heald lever.
 10. In a loom according to claim 8, in which said cam and in which said camming surface thereon comprises an arcuate camming surface controlling actuation and travel of said heald shaft lever.
 11. In a loom according to claim 8, in which said rocking device comprises a cam follower connected to said heald lever and coupling the heald lever to said rocking device, and said transfer means comprises means engaging said cam in said transfer means to said cam follower transferring control of the heald lever between the rocking device and the second drive mechanism. 